Typical features of passive keyless entry/passive start (PEPS) security systems for vehicles are that the vehicle doors automatically unlock when an authorized key fob is brought near the vehicle, and the vehicle can be started by pressing a button instead of using a key if the key fob is within the vehicle. It has been discovered that some PEPS systems can be deceived using a two-transceiver/two-person method commonly called a ‘relay attack’. The method deceives the vehicle security system by relaying the normally short-range request/reply communications commonly associated with PEPS systems over relatively long distance without the owner's knowledge. One relay device is located close to the car and a second relay device is positioned close to the car owner carrying a PEPS key fob. Then, in response to pulling a door handle or pushing a start button, the first relay receives a request signal transmitted by the vehicle security system, and relays the information to the second unit relay unit. The second relay unit retransmits the signal to the PEPS key fob. The PEPS key fob will automatically reply to this retransmitted signal which is relayed back to the vehicle to unlock the door or allow the vehicle to be started.